Detection of Metoprolol in Human Biofluids and Pharmaceuticals via Ion-Transfer Voltammetry at the Nanoscopic Liquid/Liquid Interface Array

Abstract

Metoprolol (MTP) is one of the most widely used antihypertensive drugs yet banned to use in sport competition. Therefore, there has been an increasing demand for developing simple, rapid, and sensitive methods suited to the identification and quantification of MTP in human biofluids. In this work, ultrathin silica nanochannel membrane (SNM) with perforated channels was employed to support nanoscale liquid/liquid interface (nano-ITIES) array for investigation of the ion-transfer voltammetric behavior of MTP and for its detection in multiple human biofluids and pharmaceutical formulation. Several potential interfering substances, including small molecules, d-glucose, urea, ascorbic acid, glycine, magnesium chloride, sodium sulfate and large molecules, bovine serum albumin (BSA), were chosen as models of biological interferences to examine their influence on the ion-transfer current signal of MTP. The results confirmed that the steady-state current wave barely changed in the presence of small molecules. Although BSA displayed an apparent blockade on the transfer of MTP, the accurate determination of MTP in multiple human biofluids (i.e., urine, serum and whole blood) and pharmaceutical formulation were still feasible, thanks to the molecular sieving and antifouling abilities of SNM. A limit of detection (LOD) within the physiological level of MTP during therapy could be achieved for all cases, i.e., 0.5 and 1.1 μM for 100 times diluted urine and serum, respectively, and 2.2 μM for 1000 times diluted blood samples. These results demonstrated that the nano-ITIES array behaved as a simplified and integrated detection platform for ionizable drug analysis in complex media.

Ion transfer at polarised liquid-liquid interfaces modified with adsorbed silica nanoparticles

“…Micro-ITIES arrays were also modified with mesoporous silica channels prepared ex-situ by a Stöber-like method [36]. The vertically aligned channels obtained have demonstrated their potential for analytical applications [37][38][39][40]. We investigated here the adsorption of silica nanoparticles onto the ITIES and their impact on the electrochemical transfer behaviour of ions (e.g.…”

Bioluminescence Resonance Energy Transfer (BRET) Based Nanostructured Biosensor for Tear Glucose Detection

“…Ic= Iw-Ig/Ig (2) Where Ig and Iw are the intensity ratio of the acceptor and donor before and after treated with glucose solution. As EDC mediated all the amine groups on the surface of GBP-Rluc with the carboxylic groups on the surface of CdTe, the bioconjugation process is non-site specific [23,30], the excess amount of either GBP-Rluc or QDs may affect the sensitivity of this sensor.…”

“…Body fluids such as urine [2][3][4], sweat [5][6][7][8] and tear [9][10][11][12] thus have been widely used as testing samples. It has been found that tear glucose level is around 5 times higher in diabetes patients than in normal people and the tear glucose has been identified to have a positive correlation with the blood glucose based on previous research [13][14][15].…”

Platinized Silica Nanoporous Membrane Electrodes for Low‐Fouling Hydrogen Peroxide Detection

“…For example, nanoporous gold electrodes have been employed for the detection of DNAs in diluted biofluids . SNM modified electrodes have also illustrated excellent antifouling ability and allowed the direct detection of a variety of targets in complex samples and rat brain with high sensitivities . Our previous study shows that the SNM modified carbon fiber microelectrode (SNM/CFME) can work stably in rat brain up to 2 h .…”